1. Field of the Invention
The present invention is in general directed to a control device and to a method for monitoring wear parts for printers and copiers. The invention is in particular provided for electrophotographically working printers and copiers.
2. Description of the Related Art
Electrophotographic printers are disclosed, for example, by German Patent Document DE 34 16 252 A1, European Patent Document EP 0 104 022 A2, German Letters Patent 1,280,605, German Patent Document DE 34 07 847 A1, and Published International Applications WO 91/13386 or WO 98/18052.
Published International Application WO 98/18052 discloses a printer with two identical printing units to which page-shaped material to be printed is supplied via a common input section. The printed material is output via a common output section.
Such printers and copiers are provided with a counting device for counting the number of printed sheets. Respective thresholds are stored in the control device for each wear part. An alarm signal is output when the number of printed sheets reaches a threshold, so that the corresponding wear part can be replaced. This prevents the printer or copier from continuing to operate with parts that are no longer suitable, which could result in the occurrence of malfunctions in the printing operation that could lead to a complete standstill of printing operations.
This monitoring of the individual wear parts assures a continuous operation of the printer or copier.
Printers and copiers, however, are often utilized in different environments, for example in climate-controlled rooms or in cool basement rooms or hot offices, and different users stress the printers and copiers in different ways. Thus, there are users who essentially print only invoicing texts having relatively little text per page. Other users, by contrast, print a great deal of text and/or images on a page and thus make significantly more intensive use of the fixing unit per page than a user who prints only little text.